Wanlu Li

A Novel Stable Miniaturized Frequency Selective Surface

In this letter, a novel miniaturized periodic element for constructing a bandpass frequency selective surface (FSS) is proposed. Compared to previous miniaturized structures, the FSS proposed has better miniaturization performance with the dimension of a unit cell only 0.061 λ × 0.061 λ , where λ represents the wavelength of the resonant frequency. Moreover, the miniaturization characteristic is stable with respect to different polarizations and incident angles of the waves illuminating. Both simulation and measurement are taken, and the results obtained demonstrate the claimed performance.

Novel Frequency Selective Surfaces with compact structure and ultra-wideband response

A novel bandstop Frequency Selective Surface (FSS) is presented, in which a unit cell consists of two metallic of spiral strips of different lengths and a dielectric substrate in the middle. Both simulation and measurement are presented to show that the FSS can realize size reduction and ultra-wideband response. By changing the lengths of some outer strips the miniaturization amount and bandwidth can be adjusted. Moreover, all these responses are stable with respect to different incident angles, which make the proposed structure more valuable for practical application.

A novel miniaturized frequency selective surface with stable performances

In this paper, a novel miniaturized band-reject frequency selective surface (FSS) is proposed, in which a unit cell consists of one metallic plane of a novel interleaving pattern and a dielectric substrate. Simulation results show that dimension of the basic structure is only 0.081λ×0.081λ, and the miniaturized performance can be further improved by changing widths of strips, distances between adjacent strips and numbers of interleaving strips. Moreover, the FSS presents excellent stability with respect to waves of both polarizations and different incident angles. Thus, the FSS is suitable for practical application in limited space.

A novel frequency selective surface with ultra-wideband polarization selective response

A novel frequency selective surface (FSS) with ultra-wideband (UWB) polarization selective response is proposed, in which a unit cell consists of two metallic plane of a novel asymmetry pattern. Simulation results prove that the FSS can realize selectivity of waves of a certain polarization with the bandwidth more than 36.5%, and for different incident angles the bandwidth can be broader. Moreover, effects of parameters of the structure on transmission performances of the FSS are researched and conclusions are presented, which provides theoretical basis for practical application.

A novel general structure of tunable frequency selective surface without bias grid

A novel, general structure of tunable frequency-selective surface that does not require additional bias networks is presented. Varactor diodes are positioned in the middle of each cell, and no via is required. Inductors between the cells provide DC connections, which also choke high frequency signal. Two FSS patterns are applied in the tunable structure. Simulation results of the two FSS patterns both show that by altering the capacitance of the varactors from 0.3 to 3.0 pF, a wide frequency tunability can be achieved, and at the same time the bandwidth becomes obviously wider.

A novel Frequency Selective Surface with compact structure and stable responses

A novel bandstop Frequency Selective Surface (FSS) using octagonal fractal structures is presented in this paper. By bending the edges inside and outside, the cell perimeter of the FSS can be effectively elongated, and therefore miniaturize the resonant frequency. And because of the symmetry configuration, the proposed FSS has achieved excellent stability for different polarizations and incident angles. In addition, the miniaturization performance can be further improved by changing the position and number of the inside loops. Each transmission performance is examined by simulation.

An overview of cancer treatment by terahertz radiation

Cancer claimed the death of over 7.6 million people each year all over the world. Many attempts have being practiced in clinical applications, yet some new technologies are believed to make up for the shortcomings of existing methods. Some latest advances have aroused interests in terahertz imaging and the biological effect as promising diagnostic methods for cancer. This review, however, taps into the biological effects of terahertz radiation as well as the possible mechanism to reveal the potentials and prospects of THz in cancer treatment.

A novel miniaturized band-pass frequency selective surface

In this paper, a novel band-pass miniaturized FSS is proposed, in which a unit cell consists of four spiral etched slot lines arranged central-symmetrically on a dielectric substrate, and the spiral elements are placed interlaced so that each element is connected to an adjacent one in another unit cell. Simulation results show the FSS has the dimension of a unit cell only 0.060λ×0.060λ, where λ represents the wavelength corresponding to the resonant frequency. And the miniaturization is stable with respect to different polarizations and incident angles. Prototype of the FSS is fabricated and tested. The measured results show very good agreement with simulated ones.

A novel double-layer semi-circle fractal multi-band frequency selective surface

In this paper, a novel double-layer frequency selective surface (FSS) is proposed. Each layer consists of two semi-circle fractal elements put into a circular structure on a dielectric substrate. Simulation by CST MICROWAVE STUDIO® is conducted to testify the characteristics of the FSS. The results show that the novel structure has three resonant frequencies in the frequency band 0–30GHz with relatively high impedance, and when illuminated by waves of different incident angles and polarizations the structure performs good stability. In addition, effects of the structures parameters on the transmission performances are discussed, which provides theoretical basis for practical applications.

Research on novel miniaturized frequency selective surfaces consist of rectangle spiral-based elements

A series of novel miniaturized frequency selective surfaces (FSS) are proposed. The unit cells of the structures consist of four rectangle spiral-shaped frequency selective surfaces arranging differently on the interface of a dielectric slab. Simulation by CST Microwave Studio is conducted to analyze the characteristics of the structure and performances are compared to that of the meander line. The results show that the novel FSSs perform much better than the meander line structure in miniaturization, and they have excellent angle stability and polarization stability, too.